/*
Copyright (C) 1996-1997 Id Software, Inc.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/
// chase.c -- chase camera code

#include "quakedef.h"

cvar_t	chase_back = {"chase_back", "100"};
cvar_t	chase_up = {"chase_up", "16"};
cvar_t	chase_right = {"chase_right", "0"};
cvar_t	chase_active = {"chase_active", "0"};

vec3_t	chase_pos;
vec3_t	chase_angles;

vec3_t	chase_dest;
vec3_t	chase_dest_angles;

void Chase_Init (void)
{
    Cvar_RegisterVariable (&chase_back, NULL);
    Cvar_RegisterVariable (&chase_up, NULL);
    Cvar_RegisterVariable (&chase_right, NULL);
    Cvar_RegisterVariable (&chase_active, NULL);
}

void TraceLine (vec3_t start, vec3_t end, vec3_t impact)
{
    trace_t	trace;

    memset (&trace, 0, sizeof(trace));
    SV_RecursiveHullCheck (cl.worldmodel->hulls, 0, 0, 1, start, end, &trace);

    VectorCopy (trace.endpos, impact);
}

void Chase_Update (void)
{
    int		i;
    float	dist;
    vec3_t	forward, up, right;
    vec3_t	dest, stop;


    // if can't see player, reset
    AngleVectors (cl.viewangles, forward, right, up);

    // calc exact destination
    for (i=0 ; i<3 ; i++)
        chase_dest[i] = r_refdef.vieworg[i]
                        - forward[i]*chase_back.value
                        - right[i]*chase_right.value;
    chase_dest[2] = r_refdef.vieworg[2] + chase_up.value;

    // find the spot the player is looking at
    VectorMA (r_refdef.vieworg, 4096, forward, dest);
    TraceLine (r_refdef.vieworg, dest, stop);

    // calculate pitch to look at the same spot from camera
    VectorSubtract (stop, r_refdef.vieworg, stop);
    dist = DotProduct (stop, forward);
    if (dist < 1)
        dist = 1;
    r_refdef.viewangles[PITCH] = -atan(stop[2] / dist) / M_PI * 180;

    TraceLine(r_refdef.vieworg, chase_dest, stop); //Add Traceline to Chasecam - Eradicator
    if (Length(stop) != 0)
        VectorCopy(stop, chase_dest);

    // move towards destination
    VectorCopy (chase_dest, r_refdef.vieworg);
}

